friendica/library/perfect-scrollbar

perfect-scrollbar

Minimalistic but perfect custom scrollbar plugin

If you want information of old versions<0.6.0, please refer to an old documentation.

Why perfect-scrollbar?

I was once working on a personal project, and trying to find the jQuery scrollbar plugin that's perfect. But there was no perfect one. That's why I decided to make one.

perfect-scrollbar is minimalistic but perfect (for me, and maybe for most developers) scrollbar plugin working with jQuery or vanilla JavaScript as well.

I hope you love it!

Demo

It's on the GitHub Pages.

What does perfect mean?

perfect means...

• There should be no css change on any original element.
• The scrollbar should not affect the original design layout.
• The design of the scrollbar should be (nearly) fully customizable.
• If the size of the container or the content changes, the scrollbar size and position should be able to change.
• New! It should work with vanilla JavaScript and major tools like NPM or Browserify.

Then perfect-scrollbar is really perfect?

• perfect-scrollbar has some requirements, but doesn't change or add any style on original elements.
• perfect-scrollbar is designed not to have width or height. It's fixed on the right and bottom side of the container.
• You can change nearly all css styles of the scrollbar. The scrollbar design has no dependency on scripts.
• perfect-scrollbar supports an 'update' function. Whenever you need to update the size or position of the scrollbar, just update.
• Additionally, perfect-scrollbar uses 'scrollTop' and 'scrollLeft', not absolute positioning or something messy.
• perfect-scrollbar supports RTL perfectly on both WebKit and Gecko based browsers.

It's cool, isn't it?

Install

NPM

The best way to install and use perfect-scrollbar is with NPM. It's registered on npm as perfect-scrollbar.

$ npm install perfect-scrollbar

Rails

In the case you would like to have perfect-scrollbar in your Rails application, there is the perfect-scrollbar-rails gem.

Manually

You can download the latest stable version with download links here. You also can find all releases on Releases.

From sources

If you want to use the development version of the plugin, use the source files which are not minified. They're in the src directory. The development version may be unstable, but some known bugs may have been fixed.

$ git clone https://github.com/noraesae/perfect-scrollbar.git
$ cd perfect-scrollbar/src
$ npm install
$ gulp # will lint and build the source code.

Bower

There is a Bower package for perfect-scrollbar as well. It is managed under the perfect-scrollbar-bower repository. The plugin is registered as perfect-scrollbar.

$ bower install perfect-scrollbar

CDNs

• cdnjs
• JSDelivr

JSFiddle

You can fork the following JSFiddles for testing and experimenting purposes:

• Perfect Scrollbar
• Perfect Scrollbar (jQuery)

Before using perfect-scrollbar

The following requirements should meet.

• the container must have a 'position' css style.
• the container must be a normal container element.
  • PS may not work well in body, textarea, iframe or flexbox.

The following requirements are included in the basic CSS, but please keep in mind when you'd like to change the CSS files.

• the container must have an 'overflow: hidden' css style.
• the scrollbar's position must be 'absolute'.
• the scrollbar-x must have a 'bottom' css style, and the scrollbar-y must have a 'right' css style.

Please keep in mind that perfect-scrollbar won't completely emulate native scrolls. Scroll hooking is generally considered as bad practice, and perfect-scrollbar should be used with care. Unless custom scroll is really needed, please consider using native scrolls.

How to use

First of all, please check if the container element meets the requirements.

<link rel='stylesheet' href='dist/css/perfect-scrollbar.css' />
<style>
  #container {
    position: relative;
    height: 100%; /* Or whatever you want (eg. 400px) */
  }
</style>

I would recommend using the plugin with NPM and CommonJS module system like Browserify.

var Ps = require('perfect-scrollbar');

Or you can just load the script file as usual.

<script src='dist/js/perfect-scrollbar.js'></script>

To initialise the plugin, Ps.initialize is used.

var container = document.getElementById('container');
Ps.initialize(container);

It can be initialised with optional parameters.

Ps.initialize(container, {
  wheelSpeed: 2,
  wheelPropagation: true,
  minScrollbarLength: 20
});

If the size of your container or content changes, call update.

Ps.update(container);

If you want to destroy the scrollbar, use destroy.

Ps.destroy(container);

If you want to scroll to somewhere, just use a scrollTop property and update.

container.scrollTop = 0;
Ps.update(container);

You can also get information about how to use the plugin from code in the examples directory of the source tree.

jQuery

As you may already know, perfect-scrollbar was a jQuery plugin. And it is as well. There's a jQuery adaptor and the plugin can be used in the same way it used to be used before.

I also recommend using NPM and CommonJS here, but it's not mandatory.

var $ = require('jquery');
require('perfect-scrollbar/jquery')($);

For sure, you can just import a built script.

<script src='dist/js/perfect-scrollbar.jquery.js'></script>

After importing it, you can use the plugin in the usual way.

$('#container').perfectScrollbar();          // Initialize
$('#container').perfectScrollbar({ ... });   // with options
$('#container').perfectScrollbar('update');  // Update
$('#container').perfectScrollbar('destroy'); // Destroy

RequireJS usage

For RequireJS loader, no need to write shim, simply import two libs:

require.config({
  paths: {
    perfectScrollbarJQuery: '.../perfect-scrollbar.jquery',
    perfectScrollbar: '.../perfect-scrollbar',
  }
  ...
})

and load perfectScrollbar in the initialiser of your app:

// for vanilla JS:
window.Ps = require('perfectScrollbar');

// for jQuery:
require('perfectScrollbarJQuery');

AngularJS + RequireJS usage

With the require.config settings above, at the beginning of your app module definition, you can have following code:

define([
  'angular',
  'perfectScrollbar',
  'perfectScrollbarJquery'
],
function (angular) {
  var app = angular.module('myApp', []);
  app.run(function () {
    window.Ps = require('perfectScrollbar');
    require('perfectScrollbarJQuery');
  });
  return app;
});

And initialise perfectScrollbar in a controller:

// by vanilla JS:
var container = document.getElementById('imgLoader');
Ps.initialize(container);
Ps.update(container);

// or by jQuery:
var imgLoader = $('#imgLoader')
imgLoader.perfectScrollbar();

Optional parameters

perfect-scrollbar supports optional parameters.

handlers

It is a list of handlers to use to scroll the element.
Default: ['click-rail', 'drag-scrollbar', 'keyboard', 'wheel', 'touch']
Disabled by default: 'selection'

wheelSpeed

The scroll speed applied to mousewheel event.
Default: 1

wheelPropagation

If this option is true, when the scroll reaches the end of the side, mousewheel event will be propagated to parent element.
Default: false

swipePropagation

If this option is true, when the scroll reaches the end of the side, touch scrolling will be propagated to parent element.
Default: true

minScrollbarLength

When set to an integer value, the thumb part of the scrollbar will not shrink below that number of pixels.
Default: null

maxScrollbarLength

When set to an integer value, the thumb part of the scrollbar will not expand over that number of pixels.
Default: null

useBothWheelAxes

When set to true, and only one (vertical or horizontal) scrollbar is visible then both vertical and horizontal scrolling will affect the scrollbar.
Default: false

suppressScrollX

When set to true, the scroll bar in X axis will not be available, regardless of the content width.
Default: false

suppressScrollY

When set to true, the scroll bar in Y axis will not be available, regardless of the content height.
Default: false

scrollXMarginOffset

The number of pixels the content width can surpass the container width without enabling the X axis scroll bar. Allows some "wiggle room" or "offset break", so that X axis scroll bar is not enabled just because of a few pixels.
Default: 0

scrollYMarginOffset

The number of pixels the content height can surpass the container height without enabling the Y axis scroll bar. Allows some "wiggle room" or "offset break", so that Y axis scroll bar is not enabled just because of a few pixels.
Default: 0

theme

A string. It's a class name added to the container element. The class name is prepended with ps-theme-. So default theme class name is ps-theme-default. In order to create custom themes with scss use ps-container($theme) mixin, where $theme is a scss map.
Default: 'default'

Example 1:

Add theme parameter:

Ps.initialize(container, {
  theme: 'my-theme-name'
});

Create a class name prefixed with .ps-theme-. Include ps-container() mixin. It's recommended to use map-merge() to extend $ps-theme-default map with your custom styles.

.ps-theme-my-theme-name {
  @include ps-container(map-merge($ps-theme-default, (
    border-radius: 0,
    scrollbar-x-rail-height: 20px,
    scrollbar-x-height: 20px,
    scrollbar-y-rail-width: 20px,
    scrollbar-y-width: 20px
  )));
}

Example 2:

Alternatively, if you don't want to create your own themes, but only modify the default one, you could simply overwrite $ps-* variables with your own values. In this case theme parameter is not required when calling .initialize() method. Remember do define your own variables before the theme.scss file is imported.

Events

perfect-scrollbar dispatches custom events.

ps-scroll-y

This event fires when the y-axis is scrolled in either direction.

ps-scroll-x

This event fires when the x-axis is scrolled in either direction.

ps-scroll-up

This event fires when scrolling upwards.

ps-scroll-down

This event fires when scrolling downwards.

ps-scroll-left

This event fires when scrolling to the left.

ps-scroll-right

This event fires when scrolling to the right.

ps-y-reach-start

This event fires when scrolling reaches the start of the y-axis.

ps-y-reach-end

This event fires when scrolling reaches the end of the y-axis (useful for infinite scroll).

ps-x-reach-start

This event fires when scrolling reaches the start of the x-axis.

ps-x-reach-end

This event fires when scrolling reaches the end of the x-axis.

You can listen to these events either with vanilla JavaScript

document.addEventListener('ps-scroll-x', function () {
  // ...
})

or with jQuery

$(document).on('ps-scroll-x', function () {
  // ...
})

Tips

Scrolling children inside perfect-scrollbar

You can natively scroll children inside perfect-scrollbar with the mouse-wheel. Scrolling automatically works if the child is a textarea. All other elements need to have the ps-child class. This is demonstrated in /examples/children-native-scroll.html

IE Support

The plugin is designed to work in modern browsers, including the very latest version of IE and Edge. Specifically, it should work in IEs >= IE10. If there is any issue in the browsers, please file it.

The patches to fix problems in IE<=9 won't be accepted.

When old IEs should be supported, please fork the project and make patches personally.

Helpdesk

If you have any idea to improve this project or any problem using this, please feel free to upload an issue.

For common problems there is a FAQ wiki page. Please check the page before uploading an issue.

License

The MIT License (MIT) Copyright (c) 2016 Hyunje Alex Jun and other contributors.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.